Long‐term follow‐up of a racially and ethnically diverse population of men with localized prostate cancer who did not undergo initial active treatment

BACKGROUND: There is limited research on the racial/ethnic differences in long‐term outcomes for men with untreated, localized prostate cancer. METHODS: Men diagnosed with localized, Gleason ≤7 prostate cancer who were not treated within 1 year of diagnosis from 1997–2007 were identified. Cumulative incidence rates of the following events were calculated; treatment initiation, metastasis, death due to prostate cancer and all‐cause mortality, accounting for competing risks. The Cox model of all‐cause mortality and Fine‐Gray sub distribution model to account for competing risks were used to test for racial/ethnic differences in outcomes adjusted for clinical factors. RESULTS: There were 3925 men in the study, 749 Hispanic, 2415 non‐Hispanic white, 559 non‐Hispanic African American, and 202 non‐Hispanic Asian/Pacific Islander (API). Median follow‐up was 9.3 years. At 19 years, overall cumulative incidence of treatment, metastasis, death due to prostate cancer, and all‐cause mortality was 25.0%, 14.7%, 11.7%, and 67.8%, respectively. In adjusted models compared to non‐Hispanic whites, African Americans had higher rates of treatment (HR = 1.39, 95% CI = 1.15–1.68); they had an increased risk of metastasis beyond 10 years after diagnosis (HR = 4.70, 95% CI = 2.30–9.61); API and Hispanic had lower rates of all‐cause mortality (HR = 0.66, 95% CI = 0.52–0.84, and HR = 0.72, 95% CI = 0.62–0.85, respectively), and API had lower rates of prostate cancer mortality in the first 10 years after diagnosis (HR = 0.29, 95% CI = 0.09–0.90) and elevated risks beyond 10 years (HR = 5.41, 95% CI = 1.39–21.11). CONCLUSIONS: Significant risks of metastasis and prostate cancer mortality exist in untreated men beyond 10 years after diagnosis, but are not equally distributed among racial/ethnic groups.